The invention relates to the known antitumor antibiotics daunorubicin (daunomycin) and doxorubicin (adriamycin) and more specifically, to said antibiotics labelled with 14.sub.C at the 14-position thereof and methods for preparing such labelled antibiotics.
Daunorubicin and doxorubicin are both known compounds. Moreover, daunorubicin an doxorubicin labelled with tritium (.sup.3 H) are also known, their preparation having been described by Carter et al, International Symposium on Adriamycin; Springer-Verlag, Berlin, p. 9, 1972. These tritiated compounds have been used for a variety of biochemical and medical studies, They are, however, of limited use because of the exchange of tritium in body fluids and the buffered solutions which are often utilized in biochemical studies.
Thus, notwithstanding the availability of tritiated daunorubicin and doxorubicin there exists a quite considerable need for daunorubicin and doxorubicin labelled with a more stable isotope and with a high specific activity.
.sup.14 C-labelled daunorubicin and doxorubicin are very important tools for studying the distribution, pharmacokinetics and metabolism of these antitumor drugs. [14-.sup.14 C]-daunorubicin and [14-.sup.14 C]-Doxorubicin have not heretofore been synthesized.